1/* ABI compatibility for 'fork' symbol in libpthread ABI.
2 Copyright (C) 2002-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20#include <unistd.h>
21#include <shlib-compat.h>
22
23/* libpthread once had its own fork, though there was no apparent reason
24 for it. There is no use in having a separate symbol in libpthread, but
25 the historical ABI requires it. For static linking, there is no need to
26 provide anything here--the libc version will be linked in. For shared
27 library ABI compatibility, there must be __fork and fork symbols in
28 libpthread.so; so we define them using IFUNC to redirect to the libc
29 function. */
30
31#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
32
33# if HAVE_IFUNC
34
35static __typeof (fork) *
36__attribute__ ((used))
37fork_resolve (void)
38{
39 return &__libc_fork;
40}
41
42# ifdef HAVE_ASM_SET_DIRECTIVE
43# define DEFINE_FORK(name) \
44 asm (".set " #name ", fork_resolve\n" \
45 ".globl " #name "\n" \
46 ".type " #name ", %gnu_indirect_function");
47# else
48# define DEFINE_FORK(name) \
49 asm (#name " = fork_resolve\n" \
50 ".globl " #name "\n" \
51 ".type " #name ", %gnu_indirect_function");
52# endif
53
54# else /* !HAVE_IFUNC */
55
56static pid_t __attribute__ ((used))
57fork_compat (void)
58{
59 return __libc_fork ();
60}
61
62# define DEFINE_FORK(name) strong_alias (fork_compat, name)
63
64# endif /* HAVE_IFUNC */
65
66DEFINE_FORK (fork_ifunc)
67compat_symbol (libpthread, fork_ifunc, fork, GLIBC_2_0);
68
69DEFINE_FORK (__fork_ifunc)
70compat_symbol (libpthread, __fork_ifunc, __fork, GLIBC_2_0);
71
72#endif
73